Dina Manzo shocked fans Monday night when she announced she is leaving the Bravo hit "The Real Housewives of New Jersey" -- and she opens up about her decision exclusively in the new Us Weekly, out Wednesday.

"I would say 99.9 percent is because of Danielle [Staub], but the other .1 percent was drama created by her," she tells Us Weekly.

For Manzo, the final straw came on the May 31 episode (taped last year), when Danielle Staub, 47, trailed by an ex-con bodyguard, showed up at the Manzo-owned catering hall The Brownstone for a charity event and caused a ruckus that ended with Staub’s escort hurling a gay slur at Manzo’s nephew.

"That whole night at The Brownstone just put me over the edge," Manzo, 38, tells Us Weekly. "Danielle became all we ever talked about! I wanted to film some fun stuff. I thought I signed on for a nice family show and it really turned in a different direction."

Staub, she adds, "will make up whatever lie she can to hurt you, and it’s dangerous. Who wants to be associated with that?"

For more from Manzo -- including one of the craziest lies Manzo claims Staub ever spread about her; details on plans to return for one special episode; and who really leaked Staub's buzzed-about sex tape -- pick up the new Us Weekly, on newsstands Wednesday.